FleetFoot

Maximum power my GS400 will ever be modded to is ~375hp.
I only drive on public roads at this point, no track use. My daily driver.

For practicality, I'd like to keep identical rim width and offset on all 4 corners to be able to rotate tires.

I have my eyes on the featherweight 16lb Enkei RpF1...saving ~10lbs per corner over the OEM 17's.

From a PURELY FUNCTIONAL HANDLING, ACCELERATION and BRAKING standpoint, what would be the "OPTIMAL":

* Rim Diameter (I'm guessing 18")
* Rim Width (I'm guessing 9" max)
* Rim Offset (Unsure)
* Tire Size (I'm guessing 245...40-series front & rear)

Well, it looks like I've almost answered my own question...

So I imagine for my limited hp, non-track use and rotatable-tire application, 17x8.5 with 245/40/17 (+2.4%) or 18x8.5 with 245/40/18 (-1.5%) would be optimal.

I'm also considering a quad of OEM G35 19x8 (19lb) / 19x8.5 (21lb) wrapped in 245/35/19 (-1.7%), 235/40/19 (-4.1%) or 225/40/19 (-2.9%) all around.

1) What do you guys think would be a true performance-optimized rim/tire combo for my car?

2) What do you guys notice while driving ultralight rims on the 2GS?

3) What would be the true performance advantages to a staggered setup for my application...given the limited hp?

I could get more grip with a wider tire on back, at the expense of higher wheel weight, more rolling resistance and lower MPG....which I also care about maintaining.

Thanks!

1QWKGS4

iTrader: (3)

Your Question is my Setup; I'm running 18x8.5 (All four) Light weight Speedline wheels on 245/40-18's with +40 offset and my car from a performance standpoint is just about perfect!

FleetFoot

Thanks 1QKGS4.

Which model of Speedline rims do you use and how much do they weigh?

What differences have you noted driving with your lightweight rims over say the OEM 17" and other rims you've tried?

ZippyGuy

iTrader: (9)

IMO the optimal set up is 18X9, offset between 35 to 44. If you wanted to use spacer for the rear you could flush it out more without fender modifications, something in the range of a 15-25mm spacer. As far as tires, 255/40-18 is going to give you best of all worlds as far as comfort and performance, not to mention rediculous selection of tires available to you.

FleetFoot

I assumed 245 width tires are the maximum width on the front axle without resorting to fender mods because thats the widest I've seen 90%+ of 2GS using...

1) So I would not want to go with an offset lower than 35mm on all 4 rims if using 18x9 and 255/40/18..?

2) So IF my offset on "all 4 rims" is 35-44mm ...THEN I can fit 255/40/18 (-6.3%) on 18x9 on the F axle with no rubbing on any axis ....even if I lower the front up to 2"..?

3) What would the optimum offset range be IF I use: a) 8.5" or b) 8" wide rims?
(since I'm shopping for used rims)

4) What is the relationship between tire Width, tire Diameter and ride Comfort?

I casually drove a GS4 with 245/35/19 F and 275/30/19 R and Tien CS coilovers and it subjectively felt extremely well "planted" on the ground in the rear....though from the dash computer, the MPG looked poor (not sure if it was due to greater rolling resistance of 275's).